What does a Surplus mean?

I was reading Victor Niederhoffer's book ( I think he was on this forum at one point) and he said something that I can't wrap my head around.

He mentions that a if the Japanese Trade Balance Surplus is lower than expected, there the US will not devalue the dollar to save American Jobs.

I know this does play some kind of fundamental role in USD/JPY but I can't wrap my mind around it. Can somebody please explain how a bashing the dollar down would help a Japanese surplus to save American jobs?

 

Same dollar manufacture input with lower USD vs. JPY = cheaper US goods for Japanese consumers with the same domestic profits in US.

 

+1

And Japanese goods are more expensive for American consumers.